Paper machinery



J BAXTER, JR

P APER MACHINERY 2v sheets-sheet 1 J osEPu BAXTER J la.

ATTORNEY.,

Filed July 21 195] 49m.. x A... a

J. BAXTER, JR

Dec. 8, 195.3

PAPER MACHINERY 2 sheets-sheet 2 Filed July 2l 1951 62' JosvePH 'BAxrEla da.

Patented Dec. 8, 1953 UNITED STATES a corporation of Ohio ,Application July 2&1, 1951', Serial No. 238,001

152 Claims. 1

This .invention .relates to apparatus kfor enecting combined screening Aami `wiping Operatims .on a liquid slurrvstock'suh particularly @Sneller .making stonk.

The invention has Special relation ,to the ifea-:iment-of .paper makin'asteck for the .dual Purpee .of redu-Clng large particles of rusa-hie fiber to a suitably Small-.size fQr reinng andalso fQr tremoving `undesiraloly vlarge particles such asfoating trash fromthe stock, and one of the primary objects of the invention is to provide,app'aratus for this dual purposeinthe form of `Va jsinglegcom- Pact .unit having high operating 1c apacity kvvhiemh will not only laccomplish 'both fpulping ,and ,screening of .the stock in t a single upass therethrough ]out which will also, deliver rvthe rejet material in yrelatively dry Icondition for AAready handling anddisposal.

In accordance with l,the invention fthe ,screeniP-and Pulpg @params lclllde 3193.11 nk havinga plurality of Aeliambers formed therein ,through which the Stock sucegsivly Dgd for treatment in Successive stages, and "@he chambers have perforate Wall portions i'orwdis- :Charging `into the surrounding portier@ Of the tankthe particles of desired smallsize, 'Withthe tank thus receiving and inter/mixing the flis- `.eiiargefi-goodvstolgirotn allthe @hamersflrstoof these chambers iaadVeI-.ltageollly Of'QQn- Yparatively 'large 'volume and contains an impeller of correspondingly'large size. which i`spre'f erablyprovided with multiple Working edges'sixieh -as -a-re yaioroled, for example, by .a cylindrical Vbrush of comparatively large Vdiameter equipped with relatively coarse bristles, thus giving Aa whipping action against fthe inertiafoifthe y-s'tock or veffective debering. Air-the Asame Iiimasince an `impeller -oi large jdiarneterhasthe -fadvantage of relatively high-peripheral speed forgamcomparwat-,lively low angular--velocity, =it#imparts desired 'high velocitytofthestock-'tending to drive-the y small particlesthrough the-fperiorate wallotthe chamber and at theJs'arne-'timeto throW-ithelarge lparticles-intogi'ihe connecting passagetolthe sec- Fondlehamlover.

"fllhis'second ohamloer-@in theatanigiis arranged phat-ge @through the perforate ivall jof @the f -rst the chamber 'before re'aohing'thejutle thi-'rdchamhen ter is .added V to the stock in the 'tegoed sham 4er? as 'isreadily dem by obtained by utilities e Freebie thls C ers well as inthe nrstjna'inbenand y-pari-,iii-l rly a brushl :having I bristles" arranged helally VtV -reen to cause 'the desiredtravel"of thelarg -pa tioles vlengthwise of the chamber. "6* vlWith"fthe two chambers constructed vvand arranged -a s`lde'soribed,` 'the third lcharriloer :forms a regeert-collecting chamber, and/itis provided with a conveyorf'screw lwhich--operaltes torcom-paot the* r-ej eet partiles as ^they .collect and Nthus' to lelinfiinate .mostlfthe waterrther'efromths:Water =being dischargedthrougli the'peforate Y:0f Jthe .Chamber :intosthe'fsurroundingipertion dime tank. 'Hua-thirdjohainhei",inay .he provided with an outlet utothe,extenior of theitank, and .ffrhis outlet .is equipped with a v, s liiabliyt. 0mm-tgl'- Weighted closure the nornnacteli liet .graduallyextrudedloylthe sorely/gin A@einT y VYunionforeasymainlineanddisposant 11e the vliquid snoekis conducted awa-v from tit further. `lnefirii-ng, orfother. .treatment as inlet pipe.

3 will deliver this reject material in semi-dry condition for convenient disposal.

Another object is to provide screening and pulping apparatus of the above character which will operate in stages first to screen the major proportion of usable fiber from the large particles and reject material, then to beat the reject from the first stage in substantially more dilute form for eiective salvaging of usable material therein, and finally to screen out useless reject and compact the same to semi-dry condition for ready disposal.

A further object is to provide multiple stage screen and pulping apparatus as outlined above which requires only a single inlet connection for the stock and a single outlet connection for the stock discharged during all stages of operation, and which does not require a sewer or likeY connection for reject material but delivers the reject in compacted and semi-dry condition for convenient manual disposal as by a shovel, wheel-` barrow or the like. f

It is also an object of the invention to provide multiple stage screening and pulpingapparatus in which the impeller employed at one or more stages of the pulping operation is a brush-like member having multiple relatively coarse bristles giving comparatively high velocity agitation and also having a whipping action against the inertia of the stock for effective deiibering with economical power requirements.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.

In the drawings- Fig; 1 is a somewhat diagrammatic perspective Cfr 4 imperforate to close the upper part of the chamber.

Below the trough 25 is a cylindrical shell 29 forming a chamber 30 of substantialll7 smaller diameter than chamber 20, for example a diameter approximately one-half that of chamber 20, and the lower portion of the wall of chamber 30 is provided with perforations 3| of substantially the same size as the perforations 21 in wall I5. As shown in Fig. 4, the bottom of trough 25 slants downwardly from one end thereof to the other, and at its lower end it is provided with a downwardly extending inlet connection 32 to the chamber 30 for delivering thereto material discharged over the wall 26 from chamber 20. A shower pipe 33 is mounted to extend across tank I above trough 25 to supply additional water for Y material delivered to trough 25.

view, partly broken away, showing screening and Y pulping apparatus in accordance with the invention;

Fig, 2 is a vertical section through the apparatus of Fig. l, the View being approximately on the line 2-2 of Fig. 3;

Fig. Sis a plan View of the apparatus with porf tions broken away to illustrate details of internal construction;

Fig. 4 is a fragmentary section on the line 4-3 i:

of Fig.`2 and also of Fig. 3; and

Fig. 5 is a fragmentary section on the line 5 5 of Fig. 3.

Referring to the drawings, which illustrate a preferred embodiment of the invention, the ap- .paratus includes a lmain casing l0 forming a within the larger end of tank I9 and providedl with a generally tangentially arranged inlet 2l extending upwardly therefrom and provided with a suitable flange 22 for connection to an The walls I5 and I6 are also formed with a tangentially arranged outlet passage 2d Vfrom chamber into a trough 25 which thus has an open connection with the interior of chamber 20 over the intervening wall portion 23. The wall l5 is provided with multiple perforations 2l along the lower portion thereof of selected size in accordance with the desired size of particles to be discharged therethrough, hole 1/8 inch in diameter being satisfactory, while the wall i6 is tank l0 and incorporating suitable liquid tight At the opposite end of chamber 33 from inlet 32 is an outlet connection 34 to the cylindrical chamber 35 at the smaller end of tank lil, the shell 36 which forms the chamber Y being shown as of smaller diameter than chamber 30 and provided with small Yperforations 3l in the wall thereof.

Within the chamber 2G is an impeller 40 having multiple working edges, and this impeller is shown as a cylindrical brush comprising a core 4l mounted on a shaft d2 provided with multiple relatively coarse bristles d3. YThe bristles are preferably not too closely spaced in order to provide adequate impeller action on the stock within the annular space between the outer surface of the brush and the walls I5 and I8. Thus for example, if the brush is 24 inches in diameter, the bristles 43 may be formed of steel wires approximately 0.125 inch in diameter and spaced approximately i6 to the square inch at the outer surface of the brush.

Within the chamber 30 is an impeller 45 also having multiple working edges, and this impeller is shown as a brush of generally cylindrical outline comprising a core l mounted on a shaft 41 .and provided with multiple relatively coarse bristles G8.

y effected by arranging, the bristles 48 in a helical row along core 436 as shown. A common drive is provided for the impellers and 55, shown as a main drive shaft 50 from a motor (not shown) which carries a pulley 5l connected through a belt 52 with a pulley 53 on the shaft fil of im- `peller 45, and a pulley 54 on shaft 4'! is in turn connected through belt 55 with a pulley 55 on the shaft 42 ofy impeller 3. lThe opposite ends of shafts 42 and lil are shown as supported by suitable bearing unitsV 5l mounted on the outside of .I seals 58.

The chamber 35 constitutes the collecting and i compacting chamber for reject material such as floating trash which is too large in size for passage through the perforations in the walls of either of chambers' 20 and 39.

Accordingly, within the chamber 35 is mounted a conveyor screw connected at its rearward end with a drive motorl mounted on the outside rof tank Y I0. The forward end of the cylindrical shell 36 A 62, and a closure door 65 for this outlet is pivoted in a bracket 66 at the top thereof and is provided meandri 511 with acounterweight indicateddiagrinninat-icallir ait-61 for normally holding the closuredoorf'i in closed; position.

WithA this arrangement in chamber 35i, reject material reaching the interior of-v chamber 35` is pickedup by screwL 60' and' carried towards'its outlet- 6'21 Witlr the screw" terminatingat alpo'sition spaced from the closure door i5-by an appreciablej distance ass'hown; for example 6'4 to 8 inches,- the accumulated reject isiirst compacted into arelatively'solid sli-1gbetween the end ofthe screw andtheidoor; WithA the water being squeezed outanddischarged throughthe perforations 31 intc-the; -srround ing'portion o'ftank I0; Then as additiona-lreject accumulates and isr forced against this shig,A the door 65 win bel opened againstits countervfeight G'Tftoeiec't gradual 'extrusionj of the; reject,V but sinceI there still remains a substantial slug'iof reject Within theoute let#pass-agel which'I actsy effectively asa seal, the discharge material 'is in the` form` o 'f' a damp sludge containing practicaly no more'liquid` than dheresto ,the individual particles therein.

In the operation of ,thed'evice'as apwhole, the sto'cllr is initially suppliedto the unit through ,the inlet lconnection 2 l preferably'after being treated in' a suitable-:settling trough orl Oth'erap'paratus for removing grit 'andlike heavy reject'material therefrom. With th'e impeller llil'rotating at even a relative1`y moderate peripheral speed, such for example as: 2400` feet'A perminute', the' stock will be* thoroughly thrash'e'd' Within the chamber 2o, with the; ends' of the bristles i 43. eiectivelyr whip'- pifngagainst the inertia ofxthe stock to tear apart tnezbungdles of `fibers and separate the usable iilehfrom the oatingitrashiand other larger particles'. The r'esliltin'gl srnalle'r particles are discharged Vthrough-"the perforations 21 into the surroundingV portion of tank' I0, Withth'e velocity' imparted' thereto by thel impeller. acting 'to 'drive e;

them throughl the perforations. At the saine timdmthiegimpeller 40 acts' to' sweep away` from the inner'surface of Walll' particles too large for passage through'th'e perforationarthus eiectively pre'ventingy,themv fromrrplugging'i or closingjythe perforatibnsfl. and theselarge particles' and floatiris. ,trash wiiiuiiimaieiy beihrown vover the' wail portion 2`6 into the: trough25:i the portion o'fiwall I'5l'efad'ing1un to' the' trouglthu's forming vai back# rallier; 'iiipeuer- 4u; 1

The" reject delivered-id chamber aofrrom iro-ugh g5f;;wil1l.repre`sent1a r'elati'i'l'elj s malll .proportion of". the stocki .originally delivered `.toichamber 20, fon example" about 10%, andlitwillibe relatively conce` vrated".since thawall'lportionl- 2'6" iis' nor"- a ovethieieveifof,stock withizithetanl rminpd Yby the" adjustedposition ci` 'the j |21 Accordingly; addiiioiiai Water isYV added as; described by 'way' of thefshowjer'pipeorl to` di;Y lute and'jwashdowninto chamber 30" the` mate rial ,collecting in troughiz-sa Theimpeiier Wis also rotated at a' substantial:` peripheral speedA to* repeat the thrashing andI Whipping actior'iF 'on' the stocke therein-y ijn-order-itor compi-'en A the de sired doeringaction- 'andi-thusto* s'ailvg'ei'subf stantially'iall usable fiber,Y fwhi'ch'vfi's* discharged thjrough;thel perforations 31 forinternii'xing with the'Y good stock discharged from' aj ch'aniber29%V With4 the'inletandn outlet connections 32and h34 spaced' at opposite endso' chamber `3`0"as shown; therewillbea: corresponding prolonged; dwell for anyfgven; particle within" th'e chamber" to assure adeduatmworiringthereon;,but ultimately partitles @o tooggfreat a sizegare".carricdaiongtoi the utirfr discharge ihichamher 35; 'thisaeiidri beingifaoilitatedf b y'j-iiieriieiicai bristleA an ment on irripeiier 4 5; as' described. Afier'th jctj particles reach chamber 3 5; the; are corrie paetjedas descrioedfby scr'vj duy and iiiiiiiatenf discharged -iri seniirdryf condition frddrfveiiieiit disposalr It Win lac'cordihgiybe seen that the present-im vention provides4k screening andV pulping appara"-y t'us' offering anumb'er" of important practical adL Va'ta'es'; Tli'eu'n'itas Whole isfo'f'SimpleL struction, requiring comparatively little" or spacefandminimum" piping connections. At the same time; it" has comparatiifely high capatj'; since the arrangement of 'circularscreeninglWal-ls makesiit practical to` construct these parts' of comparatively thin' plate material offering lo'v' frictional losses' andj which atth'e same time are selfrsupporting. Furthermore; since the action of theirnpellers' inj this construction Will in lii" ently lminimizeY plugging of the screerij haies either by' goody st'o'clior by reject material, sub`= stantially all the pcrforations are used at tiines formaximum 'eiciencr'i and it' will also 'b eapi parent that the screen portions canv readilyb formed as separately'replaceable parts in' the event of wear.

The arrangementjof' th'esever'al chambers'and impellers in c'oncentricrelation minimizes vibri tions and other stress ontlie' equipment, giving smooth and relatively'nois'eless' operation". Fur thermore, with all of the" chambers closdas shown, there is no probiern of splashingof the stock', and also undesirable'vaporssuch as' niiglit result during the treatment; of hot stock'are/re-y duced to a rninirmnn.V lsothe arrangement pro;

viding for dlivrjf'tl'l rjclrnatei'ali Sz''i-y dry condition for convenient disposal is highlj`r desirable, andir-i practiceit "found that tl' 'api paratus Will salvage Subs'tr'iti'ally'all usgble'l'j in. the stockV and. wiiiat the same time' effect suis stantially complete screeningand reinoval of the oating trashv and-other undesired large particles.'

While. theform ofl apparatus vherein described constitutes preferred-v'embodimentsof the' invention, itis tobefunderstoodthat the invention-is not limited to thisfprecise fornr of apparatusand that changes mayfbe made-therein wthoutnde-l parting fromf theI scope .ofthe invention-A which isi.

defined in the appended claims@ Whatis claimed-frisur,rv 1. Apparatus for screening and pulpijnggaliq-e uid slurry stock-comprisingha casing iorming. a tank adapted torhelfi-lled-rwi'thliquid, a shellr. forming arstchamberof substantia-llengthr Withinsaid having-anin-letl for saj-iolstool,Yl` saidshell including aperiorate lower Wallior" discharging particles below a predetermined:

maximum sizev into said tank, Van impeller rolI tatable. on an axis generally lengthwise' of saidf. iirst chamber causing-essentially ci'rc'uii'if'er'ential"- to said second' chamber; said second sh-eii irr:4

ticles therein and discharge of the resulting smaller particles into said tank, means for effecting a prolonged dwell of said large particles in said second chamber, a third shell forming a third chamber within said tank connected to receive from said second chamber particles of a size too great for passage through said perforate second shell wall, means within said third chamber for compacting particles received therein, said third shell having a perforate wall for discharging liquid from said compacted particles into said tank, and means for removing said compacted particles from said third chamber substantially free of liquid.

2. Apparatus for screening and pulping a liquid slurry stock comprising a casing forming a tank adapted to be filled with liquid, walls forming a plurality of chambers within said tank, means for delivering stock into the first said chamber, an impeller mounted for rotation within said first chamber and arranged to cause essentially circumferential travel of said stock therewithin while eiecting reduction of large particles within said stock, a portion of the wall of said rst chamber being perforate to discharge particles below a predetermined maximum size into said tank, means forming a passage extending lengthwise of said rst chamber for receiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an impeller mounted for rotation within said second chamber for beating said stock to eiect further reduction of large particles therein and discharge of the resulting smaller particles into said tank, means for effecting a prolonged dwell of said large particles in said second chamber, means for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, means within said third chamber for ccmpacting particles received therein, a portion vof the wall of said third chamber being perforate for discharging liquid fromsaid compacted particles intosaidtank, and means for removing said compacted particles from said third chamber substantially free of liquid.

3. .Apparatus for screening' and pulping a liquid slurry stock comprising a casing forming a tank adapted to be filled with liquid, walls forming a plurality of chambers within said tank, means for delivering stock into the rst said chamber, said first chamber including` a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an impeller mounted for rotation within said first chamber and arranged to cause essentially circumferential travel of said stock therewithin while effecting reduction of large particles within said stock, an inlet connection forming a passage extending lengthwise of said first chamber for receiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, means for adding liquid to the stock within said second chamber, an impeller 'mounted for rotation within said second chamber for beating said stock to eect further reduction of large particles and discharge of the resulting smaller particles into said tank, an outlet connection for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, said inlet and outlet connections beingspaced adjacent opposite ends of said second chamber to provide a prolonged dwell for said stock within said second chamber, means within said third chamber for compacting particles received therein, said third chamber having a perforate wall portion for discharging liquid from said compacted particles into said tank, and means for removing said compacted particles from said third chamber substantially free of liquid.

4. Apparatus for screening and pulping a liquid slurry stock comprising a casing forming a tank adapted to be illed with liquid, walls forming a plurality of generally cylindrical chambers within said tank, means for delivering stock into the rst said chamber, a generally cylindrical impeller mounted for rotation within said first chamber and having multiple working edges thereon and arranged to cause essentially circumferential travel of said stock therewithin while effecting reduction of large particles therein, said first chamber and said impeller being of relatively large diameter to provide substantial peripheral speed for said impeller, a portion of the wall of said rst chamber being perforate to discharge into said tank particles below a predetermined maximum size, Yan inlet connection forming a passage extending lengthwise of said first chamber for receiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a Vperforate wall portion for discharging particles below a predetermined maximum size into said ktank, an impeller mounted for rotation within said second chamber for beating said stock to effect further re' duction of large particles into said tank, an outlet connection for conveying to the third said chamber particlesy of a size too great for passage through said. perforate second chamber wall, said inlet andoutlet connections being spaced adjacent opposite ends of said second chamber toprovidea prolonged dwell for said stock with# in said second'chamber, means within said third chamber for compacting particles received therein, said third/.chamber having a perforatewall portion for discharging liquid'fromA said compacted'particles into said tank, and meansfor removing said compacted particles, from said third chamber substantially free 'of liquid,

5.V Apparatus for screening and pulping a liquid. slurry stock comprising a casing forming a tank adapted to be filled with liquid, walls forming a plurality of generally cylindrical chambers within said tank, meansV Vfor delivering stock into the first said chamber, means forming a passage extending along the upper side of said first charnber and leading tothe second said chamber, the wall of said first chamber below said passage beingperforate to discharge into saidtank particles below a predetermined maximum size. an impeller within said first chamber and arranged to cause essentially ycircumferential travel of said stock therewithin while Veffecting reduction of large particles therein, means Ifor rotating said impeller in a direction to discharge small particles through said perforate wall and to sweepk larger particles circumferentially upwardly along said wall into said passage for delivery into said second chamber, said second chamber including a perforatewall portion for discharging particles below a predetermined.maximumsize into said tank, an impeller mounted Aforfrotationwithin said second. chamber forbeating said stock to effect iure ther reduction of large particles therein and discharge of the resulting smaller particles into said tank, means for effecting a prolonged dwell of said large particles in said second chamberx means for conveying to the. third said chamber particles of a size too great for passage through said periorate second chamber wall, means within said third chamber for compacting particles received therein, a portion of. the wall of said third chamber being perforate for discharging liquid from said compacted particles into said tank, and means for removing said compacted particles from said third chamber substantially free of. liquid.

6, Apparatus for screening and pulpng a litis uid slurry stock comprising a casing forming. a tank adapted to be filled with liquid, walls .forming a plurality of generally cylindrical chambers within said tank, means for delivering stock into the first said chamber, means forming a trough located within said tank, means forming a passage extending lengthwise of said first chamber and leading to said trough, said trough having the bottom located below the upper end of said 1 passage, the wall of said first chamber below said passage being periorate to discharge into said tank particles below a predetermined maximum size, an impeller within said rst chamber and arranged to cause essentially circumferential .1

portion ior discharging particles :below a predetermined maximum size into said tank, an im: peller mounted for rotation within said second chamber for beating said stock to eliect further reduction of large particles therein and discharge of the resulting smaller particles into said tank, y;

means for eiiecting a prolonged dwell of said large particles in said second chamber, means for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, means within said L third chamber for compacting particles received therein, a portion of the wall of said third chamber being perforate for discharging liquid from said compacted particles into said tank, and means for removing said .compacted particles from said third chamber substantially free of liquid.

7. Apparatus for screening and pulping a hquid slurry stock comprising a casing forming a tank adapted to be filled with liquid, Walls vforming a plurality of generally cylindrical chambers within said tank, means for delivering Stock llto the rst said chamber, means forming a passage extending along the upper side of said lSt chamber and leading to the second said chamber, the wall ofsaid first chamber below said passage pas ing perforate to discharge into said tank. particles below a predetermined maximum size, an im-Y peller within said first chamber including a generally cylindrical brush having relatively coarse bristles thereon providing multiple Working edges for 'eiecting reduction of large particles lll said stock upon rotation thereof, means for rotating said impeller in a direction to discharge small particles through said perforatc wall and to sweep larger particles cireumierentially upwardly along said wall. into said passage for delivery into said second chamber, said second chamber including. a periorate wall portion for discharging particles below a predetermined maximum Size .into said tank, an -irnpeller mounted for rotation within said second chamber for beating said stoolsi to eliect further reduction of large particles therein and discharge of the resulting smaller particles into said tank,v means for effecting a prolonged dwell of said large particles4 in said sec-s. ondchamber, means for conveying to the third said chamber particles of a Size too great .for pas= sage through said. perforate Second chamber wall. means within said third chamber vfor compactne particles received therein. a portion of the wall of Said; third chamber being perforate for. dis: charging liquid from said compacted particles into said tank, and means; for removing said coms pacted particles from said third chamber sub. Stantially free of liquid.

8, Apparatus for Screening and loulpingl a.. liquid slurry stock; comprising a casing forming a. teni; adapted to be lledwith liquid, walls forming a plurality of. chambers within said tank, means for delivering stock into the first said chamber, said iirst chamber including a perforate wall portion for-discharging particles below a pre.e determined maximum size into said tank, anime ,peller mounted for `rotation within said first chamber and arranged to cause essentially oirH cumferential travel oi Said. Stock therewithin while. effecting reduction of large particles within said. stock, an inlet connection forming a passage extending lengthwise of. said first chamber for receiving therefrom particles greater than said maximum size and delivering Asaid particles to said second chamber, said second chamber in. oluding a perforate wall portion for discharging particles below a predetermined .maximum size into said tank. an outlet connection for conveys ing to the third said chamber particles of a site too great .for passageithrough said perforate sec 0nd chamber wall. Said inlet and outlet connec- H tions being spaced adjacent opposite ends of said second chamber to provide a prolonged dwell for said stock Within said second chamber, an impeller mounted for rotation within saidsecond chamber for beating said stock to effect iurther reduction o f large particles therein and discharge of the resulting smaller particles into said tank,

said impeller having a plurality of bristles thereon arranged to cause said large particles to travel clrcumferentially of said second chamber while progressing from said inlet connection to said outlet connection as said impeller rotates, meansv o slurry stock comprising a casing forming a tank adapted to be filled with liquid, walls forming a plurality of chambers within said tank, means for delivering stock. .hito the first said chamber, an impeller mounted for rotation within said rst chamber and arranged to cause essentially circumferential travel of said stock therewithin while effecting reductionof. large particles within sa1d stock, a portion of the Wall of said first .encina ber being periorate to discharge particles below a l predetermined maximum size into said tank.

ll Y v means forming a passagegextending lengthwise of said first chamber forrreceiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, an impeller mounted for rotation within said second chamber for beating said stock to eiect further reduction of large particles therein and discharge of the resulting smaller particles into said tank, means for eiecting a prolonged dwell of said large particles in said second chamber, means for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, said third chamber being generally cylindrical, a conveyor screw mounted for rotation within said third chamber, means for rotatingsaid screw to effect compaction of the particles within said third chamber, a portion ofthe wall of said chamber being perforate to discharge into said tank the liquid from said compacted particles, said third chamber having an outlet located exteriorly of said tank, and a counterweighted closure on said outlet for cooperation with said screwA to effect said compaction of said particles and discharge of said compacted particles substantially free of liquid.

10. Apparatus for screening and pulping a liquid slurry stock comprising a casing forming a tank adapted to be lled with liquid, walls forming a, plurality of chambers within said tank, means forY delivering stock into the rlrst said chamber, said rst chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an impeller mounted for rotation within said rst chamber and including a generally Vcylindrical brush having relatively coarse bristles thereon providing multiple working edges for causing essentially circumferential travel of saidrstock within said chamber while eifecting reduction` of large particles in said stock, an inlet connection forming a passage extending lengthwise of said rst chamber for receiving therefrom par- .ticles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an outV let connection for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, said inlet and outlet connections being spacedv adjacent opposite ends of said second chamber to provide a prolonged dwell for said stock within said second chamber, an impeller mounted for rotation within said second chamber for'beating said stock to effect further reduction of large particles therein and discharge of the resulting smaller particles into said tank, said impeller having a plurality of bristles thereon arranged to cause said large particles to travel circumferentially of said second chamber while progressing from said inlet connection to said outlet con'- nection as said vimpeller rotates, means within said third chamber for compacting particles re'- ceived therein, said third chamber having a perforate Vwall portion for discharging liquid from said compactedl particles into said tank, and means for removing said compacted parti'- cles `from said third chamber substantially free of liquid. Y

1l. Apparatus for screening and pulping a liquid slurry stock comprising a casing forming a tank adapted to be filled with liquid, walls forming a plurality of generally cylindrical chambers within said tanmans for delivering stock inter the iirst said chamber, an impeller mounted for' rotation Within said iirst chamber and including a generally cylindrical brush having relatively coarse bristles thereon providing multiple working edges. for causing essentially circumferential travel of said stock within said chamber whilef effecting reduction of large particles in said stock,-

a portion of the wall of said first chamber being perforate to discharge into said tank particles below a predetermined maximum size, an inlet connection forming a passage extending lengthwise of said rst chamber for receiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a perforate wall portion for discharging particles below a prede? tei-mined maximum size into said tank, an outlet connection for conveying to the third said chamber particles of a size too Ygreat for passage through said perforate second chamber wall, said inlet and outlet connections being spaced adjacent opposite ends of said second chamber to provide a prolonged dwell for said stock within said second chamber, an impeller mounted for rotation within said second chamber for beating said stock to eifect further reduction of large particles therein and discharge of the resulting smaller particles into vsaid tank, said impeller having a plurality of bristles thereon arranged' to cause said large particles to travel circumferentially of said second chamber While progressing from said inlet connection to said outlet connection as said impeller rotates, means Within said third chamber for compacting particles received therein, said third chamber having a perforate wall portion for discharging liquid from said compacted particles into said tank, and means for removing said compacted C particles from said third chamber substantially free of liquid.

l2. Apparatus for screening and pulping a liquid slurry stock comprising a tank adapted to be lled with liquid, walls forming a plurality of generally cylindrical chambers within said tank, means for delivering stock into the rst said chamber, said first chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an impeller mounted for rotation within said first chamber and including a generally cylindrical brush having coarse bristles for causing essentially circumferential travel of said stock within said chamber while effecting reduction of large particles within said stock, an inlet connection forming a passage extending lengthwise of said rst chamber for receiving therefrom particles greater than said maximum size and delivering said particles to said second chamber, said second chamber including a perforate wall portion for discharging particles below a predetermined maximum size into said tank, an outlet connection for conveying to the third said chamber particles of a size too great for passage through said perforate second chamber wall, said inlet and outlet connections being spaced adjacent opposite ends of said second chamber to provide a prolonged dwell for said stock Within said second chamber, an impeller mounted for rotation within said secondchamber for effecting further reduction of large particles therein and discharge of the resulting smaller particles into said tank, said impeller having a plurality of bristles thereon arranged to cause said large particles to travel crcumferentially of said second 13 chamber while progressing from said inlet connection to said outlet connection as said impeller rotates, a conveyor screw within said third chamber, means for rotating said screw to effect compaction of the particles within said third chamber, said third chamber having a perforate wall portion to discharge into said tank the liquid from said compacted particles, said third chamber having an outlet located exterorly of said tank, and a counterweghted closure on said outlet for cooperation with said screw to effect said compaction of said particles and discharge of said compacted particles substantially free of liquid.

JOSEPH BAXTER, Jn.

References Cited in the le of this patent UNITED STATES PATENTS Number Number i6 234,4 18

Name Date Cook Sept. 18, 1900 Sherwood Dec. 1, 1908 n Shartle Feb. 7, 1922 Shartle Mar. 25, 1924 Rose Oct. 7, 1924 Shartle Apr. 27, 1926 Thorne l- Sept. 3, 1935 FOREIGN PATENTS Country Date Germany July 10, 1910 

